1. Field
Embodiments of the present invention relate generally to vehicle telematics. More specifically, embodiments relate to wireless, internet-based systems that collect, transmit, and analyze diagnostic and location-based data from a motor vehicle.
2. Description of Related Art
Telematics systems typically collect data from a remote vehicle and wirelessly transmit these data to a central computer system. The computer system then analyzes the data to monitor the vehicle. Conventional telematics systems collect diagnostic data, measured from the host vehicle's engine computer, and location-based data, measured with a global positioning system (GPS).
Telematics systems that monitor light-duty automobiles and trucks beginning with model year 1996 measure data from the vehicle's on-board diagnostic (OBD-II) system. OBD-II systems, as mandated by the Environmental Protection Agency (EPA), monitor the vehicle's electrical, mechanical, and emissions systems and generate data that are processed by an engine control unit (ECU) to detect malfunctions or deterioration in the vehicle's performance. Communication protocols used to access OBD-II data include J1850 PWM (Ford vehicles), J1850 VPWM (General Motors), ISO 9141-2 (Toyota), KWP2000 (Hyundai, Mercedes), and CAN (proposed for next-generation vehicles). Data monitored with these protocols typically include parameters such as vehicle speed (VSS), engine speed (RPM), engine load (LOAD), and mass air flow (MAF). The ECU can also generate diagnostic trouble codes (DTCs), which are 5-digit codes (e.g., ‘P0001’) indicating electrical/mechanical problems with the vehicle. Most vehicles manufactured after 1996 include a standardized, 16-cavity serial connector that makes these data available. This OBD-II connector serially communicates with the vehicle's ECU and typically lies underneath the vehicle's dashboard.
The primary communication protocol for collecting diagnostic data from medium and heavy-duty trucks is called J1708/J1587 (referred to herein as ‘J1708’). This communication protocol, which originated in 1988, typically accesses a set of data that is much larger than that available from light-duty cars and trucks. Most medium and heavy-duty trucks include a 6-cavity connector, which connects to the truck's engine computer to make these data available.
A variety of wireless networks can transmit diagnostic and GPS data from a vehicle's telematics device to the central computer system. Terrestrial networks, i.e. networks with terrestrial base stations or transmitting towers, include CDMA networks (managed by Sprint and Verizon), GSM/GPRS networks (ATT, T-Mobile), Mobitex (Cingular), DataTac (Motient), and Reflex (Arch Pagenet, Weblink Wireless). These networks typically have good coverage within a given country's major population centers, but poor coverage in rural, un-populated areas. And individual terrestrial networks typically do not offer coverage in multiple countries. Satellite networks (managed, e.g., by Orbcomm or Globalstar) typically transmit data with lower bandwidth and higher costs compared to terrestrial networks, but offer near-worldwide coverage.